Remove label from a can of condensed milk and place in a deep saucepan filled with water, covering the can completely.
Bring to a boil, cover and boil for 2 1/2 hours. *Make sure to check and keep the can completely submerged the entire time.
Remove the can from the boiling water, let cool, and open. YOU JUST MADE TOFFEE!
You can keep sealed in the can and use at a later time (keeps for months!) or use right away.
Now make your whipped cream using a COLD (I store mine in the freezer an hour before using) bowl and beater.
Add heavy cream, vanilla, and brown sugar to bowl and whip on high until fluffy and soft peaks form.
Keep refrigerated until ready to use.
Peel and slice bananas into thin slices.
Lay banana slices in the pie shell, pour can of toffee on top, spreading to cover, then top with mounds of whipped cream.
Refrigerate to firm up until ready to serve.